In Situ Evolution of the Frozen Layer Under Cold Anode

Utilization of Waste Heat for Pre-heating of Anodes

“…The layered structure seen in figure 9b as been observed on anodes previously [2,3,10], but also on rafts [11], albeit with lower porosity and smaller pore size. As observed by Poncsak et al [10], the frozen bath is more compact close to the surface where it first freezes -i.e.…”

“…940-970 • C [1]. Due to this temperature difference, a layer of frozen bath will form underneath the new anode, which, depending upon process conditions will melt within some hours after insertion [2,3]. The thermal imbalance and frozen bath layer introduces a latency in production, affects the bath density [2] and disturbs the MHD stability of the cell [4].…”

Heating New Anodes Using the Waste Heat of Anode Butts Establishing the Interface Thermal Contact Resistance

“…Carbon anodes are replaced on a regular basis in aluminum electrolysis cells as they are consumed by electrochemical reactions [1]. Upon insertion of new anodes, bath will freeze locally as a result of low bath superheat and comparatively low anode temperature, creating an insulating layer on the anode surface, thereby delaying and disrupting further production [2,3,4]. Moreover, the heating of the newly inserted anode comes at an energy premium of approximately 0.13 kWh/kg produced Al.…”